1. Technical Field
The present invention relates to a liquid discharging apparatus, a head unit, and a control method of a liquid discharging apparatus.
2. Related Art
A liquid discharging apparatus such as an ink jet printer forms images on a recording medium by discharging a liquid such as ink, with which a cavity (a pressure chamber) of a discharge section is filled, as a result of displacing a piezoelectric element provided in the discharge section. In such a liquid discharging apparatus, there are cases in which a discharge abnormality, in which it is no longer possible to normally discharge a liquid from a discharge section, occurs as a result of thickening of the liquid inside a cavity, the incorporation of an air bubble in the cavity or the like. Further, when a discharge abnormality occurs, it is no longer possible to correctly form intended dots, which are formed on a recording medium by a liquid that is discharged from a discharge section, and therefore, the image quality of images that the liquid discharging apparatus forms, is reduced.
In JP-A-2004-276544, a technique that prevents a reduction in image quality due to a discharge abnormality by detecting residual vibrations that occur in a discharge section after displacing a piezoelectric element through driving thereof, and determining a discharge state of a liquid in the discharge section on the basis of the characteristics of the residual vibrations such as the period length and amplitude of the residual vibrations, is suggested.
Incidentally, there are cases in which a liquid is discharged from a discharge section when a piezoelectric element is displaced in order to determine a discharge state of the liquid in the discharge section. In this case, there are problems in that the recording medium can become stained by the discharged liquid, and liquid is consumed in order to determine the discharge state.
Meanwhile, in the determination of a discharge state, in order to prevent the occurrence of problems caused by liquid being discharged from a discharge section, there are cases in which a piezoelectric element is displaced by a small amount of an extent at which liquid is not discharged from the discharge section. However, in this case, the residual vibrations, which are generated in the discharge section, are small, and therefore, there is a problem in that it is no longer possible to correctly determine the discharge state of the liquid in the discharge section.